FORT WORTH, Texas — Jimmie Johnson is the leader again in the Chase for the Sprint Cup title after a dominating victory Sunday at Texas Motor Speedway.

The five-time Cup champion knows all too well that his seven-point lead over Matt Kenseth is far from overwhelming with two races left in the season.

Johnson also left the Lone Star State last November with a victory and seven-point lead — and lost the championship to Brad Keselowski.

“I hope history doesn’t repeat itself,” Johnson said. “That is the perfect example of this thing isn’t over until it’s over. Last year we had eight great races and two bad ones and didn’t get the championship. ... There are two very important races left.”

Kenseth and Johnson were tied in points when they got to Texas, though Kenseth was considered the leader based on his seven wins.

Johnson led 255 of 334 laps for his sixth win this season while becoming only the second three-time Cup winner at the high-banked 1½-mile Texas track. The No. 48 Chevrolet finished more than 4 seconds ahead of Hendrick Motorsports teammate Dale Earnhardt Jr.

“The 48 was in another class and nobody had anything for them,” said Earnhardt, who had his fifth runner-up finish this season and has been top 10 in all six of the last seven Chase races.

Johnson got his 66th career victory, including a record 24 wins in Chase races.

But he and crew chief Chad Knaus are now in their third season since winning their fifth consecutive championship.

“I’ve been watching a lot of MMA fighting lately, and you’ll fall into a rhythm and think that somebody’s got a fight won, and it doesn’t end that way,” Johnson said. “It’s how this is going to be. Matt didn’t have maybe the best day, but he still finished fourth. This thing is going to the last lap at Homestead. It’s going to come down to mistake.”

Kenseth was running second behind Johnson for much of the first half of the race before getting penalized for speeding. That dropped Kenseth to 16th place and more than 28 seconds back, though the No. 20 Joe Gibbs Racing Toyota recovered for a top-five finish.

“We were just being too aggressive. Honestly, the 48 had us ... they were just dominant all weekend,” Kenseth said. “That speeding penalty got us behind us. We definitely didn’t need that, but really I don’t know at the end of the day that it really affected our finish much.”

At Phoenix, where the Chase goes next Sunday, Johnson is a four-time winner and finished second in March. His average finishing spot of 6.4 there is significantly better than the 17.2 for Kenseth, who has one victory at Phoenix and finished seventh there eight months ago.

“I’m still confident,” Kenseth said.

Kenseth was still running second when Johnson pulled down pit road, a lap before Kenseth came in as the last to pit on a cycle of green-flag stops.

But Kenseth was caught speeding on pit road and had to serve a drive-through penalty. By time he got back on the track, he was the last car on the lead lap and about 25 seconds further behind than he had been before the two had pitted.

A caution a few laps later got Kenseth up three spots, but more importantly tightened up the field. Within a few laps after the ensuing restart, Kenseth was back in the top 10 and climbing.

By then, Kyle Busch had moved back into second, the same spot he was before a right front tire went down and put into in the outside wall on lap 57 to bring out a caution. Busch, who won the spring race in Texas, finished 13th.

When Busch went into the wall, he was between Johnson and Kenseth, who went onto pit road 1-2. The top Chase contenders didn’t exit that way.

While Johnson had a quick stop, he was second out behind polesitter Carl Edwards, who had the stall closest to the scoring line. Kenseth has an issue on his stop that dropped him to sixth.

Edwards, who had been the only three-time Cup winner at Texas, led six times for 38 times. But Edwards finished only 187 laps before an engine failure ended his day.

Four-time Cup champion Jeff Gordon, the other Hendrick driver, was in contention for another championship after his win a week earlier at Martinsville moved him up to a season-high third in points.

But on Lap 74, the front left tire on the No. 24 Chevrolet blew, sending Gordon high and hard into the wall between the first and second turns. His returned to the race after repairs and finished in 38th place, 187 laps off the pace. He dropped to sixth the standings, 67 points back.

“I just know that the left front went down as I was going down the front straightaway. I felt it before I got there, and I just couldn’t get it slowed down enough,” Gordon said. “I don’t know; the wind was so strong that the car was doing funky things down the straightaways. I don’t know if that was a slow leak, or if it just went all of a sudden. Our car just didn’t take off very good, but boy was it strong on the long runs.”